I had a sudden oven failure in my older 30" RNB, and happened to see the obvious cause. I don't have a wiring diagram, but the circuit is so simple that it's not really necessary. The line from the plug goes along the side of the range to the control knobs, spark unit and igniters. It delivers 120v to the thermostat. When the oven or broiler is switched on, the thermostat passes that 120V back to the thermovalve, which in turn sends it down to the appropriate oven or broiler igniter, which in turn connects directly to the neutral wire from the plug.

My range's problem was caused by a misrouting of the wires that bring power up to the oven igniter. Instead of having been passed through the big hole that's obviously provided for them at the front of the range, they were pinched between the side panel and frame of the range, squeezing them very tightly. Finally the insulation degraded enough to cause a short, with a moment of sparking that made the location of the problem obvious.

The short damaged the internal circuitry in the thermovalve, which is not protected by a fuse, so the thermovalve is shot. It only hurt the oven-side circuitry; the broiler, which is handled by the same valve, is fine.

It's conceivable that such a short would knock out the thermostat, but in my case it didn't. I will have to replace the thermovalve and the wires going to the igniter, rerouting them to avoid a repeat performance.